Sidebar JS issue in 4.0.0

[curtic00]

This is shown in the log stream:

09-22T17:20:43.3021111Z fail: Microsoft.AspNetCore.Components.Server.Circuits.CircuitHost[111]
2026-09-22T17:20:43.3021656Z Unhandled exception in circuit 'KFlpGpXdRn1ZUguwIDtxmoHK1dlSye8CC82A_zLotG0'.
2026-09-22T17:20:43.3034059Z Microsoft.JSInterop.JSException: Could not find 'window.blazorBootstrap.sidebar.initialize' ('blazorBootstrap' was undefined).
2026-09-22T17:20:43.3034251Z E@https://www.*****.org/_framework/blazor.web.9hsif5t8mt.js:1:6757
2026-09-22T17:20:43.3034296Z resolveInvocationHandler@https://www.***.org/_framework/blazor.web.9hsif5t8mt.js:1:380
2026-09-22T17:20:43.303433Z processJSCall@https://www.*****.org/_framework/blazor.web.9hsif5t8mt.js:1:4441
2026-09-22T17:20:43.3034364Z beginInvokeJSFromDotNet@https://www.*****.org/_framework/blazor.web.9hsif5t8mt.js:1:4138
2026-09-22T17:20:43.3034546Z _invokeClientMethod@https://www.*****.org/_framework/blazor.web.9hsif5t8mt.js:1:69353
2026-09-22T17:20:43.3034592Z _processIncomingData@https://www.*****.org/_framework/blazor.web.9hsif5t8mt.js:1:66732
2026-09-22T17:20:43.3034626Z @https://www.*****.org/_framework/blazor.web.9hsif5t8mt.js:1:84431
2026-09-22T17:20:43.3034663Z at Microsoft.JSInterop.JSRuntime.InvokeAsync[TValue](Int64 targetInstanceId, String identifier, JSCallType callType, Object[] args)
2026-09-22T17:20:43.30347Z at Microsoft.JSInterop.JSRuntimeExtensions.InvokeVoidAsync(IJSRuntime jsRuntime, String identifier, Object[] args)
2026-09-22T17:20:43.303477Z at BlazorBootstrap.BlazorBootstrapComponentBase.SafeInvokeVoidAsync(String identifier, Object[] args)
2026-09-22T17:20:43.3034803Z at BlazorBootstrap.Sidebar.OnAfterRenderAsync(Boolean firstRender)
2026-09-22T17:20:43.3034841Z at Microsoft.AspNetCore.Components.RenderTree.Renderer.GetErrorHandledTask(Task taskToHandle, ComponentState owningComponentState)

A clear and concise description of what the bug is.

To Reproduce
Steps to reproduce the behavior:
Upgrade Balzor server app to version 4.0.0
run in Ubuntu web app

Expected behavior
Log stream should not show such error

Versions (please complete the following information):

• .NET Version: .NET 10
• BlazorBootstrap:4.0.0
• Blazor Server: [e.g. WebAssembly, Server]
• Blazor Interactive Render Mode: Server,
• Blazor Interactivity Location: Global

Sample code
@inherits LayoutComponentBase

<Sidebar @ref="sidebar"
         Href="/"
         ImageSrc="../Manager.ico"
         Title="Simpson Jobs"
         DataProvider="SidebarDataProvider" />

<main>
    <div class="gDesktop bb-top-row px-4  justify-content-between ">
        <Icon Name="IconName.List" role="button" @onclick="ToggleSidebar"  />
        <AuthorizeView>
            <Authorized>
                Hello, @context.User.Identity?.Name!
                <a href="MicrosoftIdentity/Account/SignOut">Log out</a>
            </Authorized>
            <NotAuthorized>
                <a href="MicrosoftIdentity/Account/SignIn">Log in</a>
            </NotAuthorized>
        </AuthorizeView>
    </div>

    <article class="px-2">
        <div class="py-1">@Body</div>
    </article>
</main>

@code {
IEnumerable navItems = default!;
Sidebar sidebar = default!;

private async Task<SidebarDataProviderResult> SidebarDataProvider(SidebarDataProviderRequest request)
{
    if (navItems is null)
        navItems = GetNavItems();

    return await Task.FromResult(request.ApplyTo(navItems));
}

private IEnumerable<NavItem> GetNavItems()
{
    navItems = new List<NavItem>
    {
        new NavItem { Id = "1", Href = "/", IconName = IconName.HouseDoorFill, Text = "Home"},
        new NavItem { Id = "MyDashBoard",  IconName = IconName.CardList, Text = "My DashBoard"},
        new NavItem { Id = "MyDashBoardBrowsing", Href = "/MyDashBoards/MyBrowsing",    IconName = IconName.CardList, Text = "Browsing",  ParentId ="MyDashBoard"},
        new NavItem { Id = "Jobs",  IconName = IconName.WrenchAdjustableCircleFill, Text = "Jobs...",    IconColor = IconColor.Primary},
        new NavItem { Id = "2", Href = "/Dashboard", IconName = IconName.CardList, Text = "DashBoard", ParentId ="Jobs"},
        new NavItem { Id = "3", Href = "/Jobs/SearchJobs", IconName = IconName.Search, Text = "Jobs: Search" , ParentId ="Jobs"},
        new NavItem { Id = "4", Href = "/Jobs/Latest", IconName = IconName.Table, Text = "Jobs: Latest", ParentId ="Jobs"},
        new NavItem { Id = "5", Href = "/Jobs/Status" , IconName = IconName.Database, Text = "Jobs: By Status", ParentId ="Jobs"},
        new NavItem { Id = "5T", Href = "/Jobs/Type" , IconName = IconName.Database, Text = "Jobs: By Type", ParentId ="Jobs"},
        new NavItem { Id = "5A", Href = "/Jobs/Create" , IconName = IconName.DatabaseFillAdd, Text = "Jobs: Create", ParentId ="Jobs"},
        new NavItem { Id = "Customers",  IconName = IconName.PeopleFill, Text = "Customers..." ,  IconColor = IconColor.Info},
        new NavItem { Id = "CustomerDetails", Href = "/Customers/CustomerDetails/" , IconName = IconName.PeopleFill, ParentId ="Customers" , Text = "Customers: Details" ,  IconColor = IconColor.Info},
        new NavItem { Id = "6",  Href = "/Customers/CustomerSearch"  , IconName = IconName.Search, Text = "Customers: Search", ParentId ="Customers" ,  IconColor = IconColor.Info },
        new NavItem { Id = "CompanyCreate",  Href = "/Customers/CustomerCreate"  , IconName = IconName.PlusCircleFill, Text = "Company: Create", ParentId ="Customers" ,  IconColor = IconColor.Info },
        new NavItem { Id = "IndividualCreate",  Href = "/Customers/IndividualCreate"  , IconName = IconName.PlusCircleFill, Text = "Individual: Create", ParentId ="Customers" ,  IconColor = IconColor.Info },
        new NavItem { Id = "CostManagement", IconName = IconName.CurrencyPound, Text = "Cost Management" ,  IconColor = IconColor.Danger},
        new NavItem { Id = "CostManagementInvoices", Href = "/Invoice/" , IconName = IconName.CashCoin, Text = "Invoicing" ,  IconColor = IconColor.Danger, ParentId ="CostManagement" },
        new NavItem { Id = "JobCostSummary", Href = "/CostManagement/JobCostSummary/" , IconName = IconName.CashCoin, Text = "Job Cost Summary" ,  IconColor = IconColor.Danger, ParentId ="CostManagement" },
        new NavItem { Id = "Admin", IconName = IconName.Gear, Text = "Admin" ,  IconColor = IconColor.Primary},
        new NavItem { Id = "Settings-WorkLogs", Class="jobCostSummary", Href = "/Settings/WorkLogs", IconName = IconName.WrenchAdjustableCircleFill, Text = "WorkLog Settings" , ParentId ="Admin"},
        new NavItem { Id = "Settings-Cache", Class="SettingsCache", Href = "/Settings/Cache", IconName = IconName.WrenchAdjustableCircleFill, Text = "Cache Settings" , ParentId ="Admin"}

    };
    return navItems;
}

private void ToggleSidebar() => sidebar.ToggleSidebar();

}

<style> :root { --bb-sidebar-width: 270px; --bb-sidebar-collapsed-width: 50px; --bb-sidebar-background-color: rgba(234, 234, 234, 1); --bb-sidebar-top-row-background-color: rgba(0,0,0,0.08); --bb-sidebar-top-row-border-color: rgb(194,192,192); --bb-sidebar-title-text-color: rgb(0,0,0); --bb-sidebar-brand-icon-color: #6f42c1; --bb-sidebar-brand-image-width: 24px; --bb-sidebar-brand-image-height: 24px; --bb-sidebar-title-badge-text-color: rgb(255,255,255); --bb-sidebar-title-badge-background-color: rgba(25,135,84,var(--bs-bg-opacity,1)); --bb-sidebar-navbar-toggler-icon-color: rgb(0,0,0); --bb-sidebar-navbar-toggler-background-color: rgba(0,0,0,0.08); --bb-sidebar-content-border-color: rgb(194,192,192); --bb-sidebar-nav-item-text-color: rgba(0,0,0,0.9); --bb-sidebar-nav-item-text-active-color-rgb: 0,0,0; --bb-sidebar-nav-item-text-hover-color: rgba(var(--bb-sidebar-nav-item-text-active-color-rgb),0.9); --bb-sidebar-nav-item-text-active-color: rgba(var(--bb-sidebar-nav-item-text-active-color-rgb),0.9); --bb-sidebar-nav-item-background-hover-color: rgba(var(--bb-sidebar-nav-item-text-active-color-rgb),0.08); --bb-sidebar-nav-item-group-background-color: rgba(var(--bb-sidebar-nav-item-text-active-color-rgb),0.08); } </style>

GitHub repo
GitHub repo with minimal code to reproduce the issue.

Desktop (please complete the following information):

• OS: windows 10
• Browser chrome, edge
• Version [e.g. 22]

Additional context
Add any other context about the problem here.
Playwright and Bunit test cases passed.
Does not seeeeeem to be any impact on application that I can tell
Did not see this in previous version of BB